Experimental Physics

To know the resistance G of a galvanometer by half deflection method, a battery of emf $V_E$ and resistance R is used to deflect the galvanometer by angle θ. If a shunt of resistance S is needed to get half deflection then G, R and S are related by the equation :

A particle of mass m is acted upon by a force F given by the empirical law $F=\dfrac R{t^2}v(t)$. If this law is to be tested experimentally by observing the motion starting from rest, the best way is to plot :

A thin 1 m long rod has a radius of 5 mm. A force of 50 πkN is applied at one end to determine its Young's modulus. Assume that the force is exactly known. If the least count in the measurement of all lengths is 0.01 mm, which of the following statements is false ?

A galvanometer has a 50 division scale. Battery has no internal resistance. It is found that there is deflection of 40 divisions when R = 2400 Ω. Deflection becomes 20 divisions when resistance taken from resistance box is 4900 Ω. Then we can conclude :

To determine refractive index of glass slab using a travelling microscope, minimum number of readings required are :

Consider a Vernier callipers in which each 1 cm on the main scale is divided into 8 equal divisions and a screw gauge with 100 divisions on its circular scale. In the Vernier callipers, 5 divisions of the Vernier scale coincide with 4 divisions on the main scale and in the screw gauge, one complete rotation of the circular scale moves it by two divisions on the linear scale. Then:

Diameter of a steel ball is measured using a Vernier callipers which has divisions of 0.1 cm on its main scale (MS) and 10 divisions of its vernier scale (VS) match 9 divisions on the main scale. Three such measurements for a ball are given as :

S.No.	MS (cm)	VS divisions
1.	0.5	8
2.	0.5	4
3.	0.5	6

If the zero error is −0.03 cm, then mean corrected diameter is :

A student is performing an experiment using a resonance column and a tuning fork of frequency $244\ \mathrm s^{-1}$. He is told that the air in the tube has been replaced by another gas (assume that the column remains filled with the gas). If the minimum height at which resonance occurs is $(0.350\pm0.005)$ m, the gas in the tube is

(Useful information: $\sqrt{167RT}=640\ \mathrm{J^{1/2}\,mole^{-1/2}}$; $\sqrt{140RT}=590\ \mathrm{J^{1/2}\,mole^{-1/2}}$. The molar masses $M$ in grams are given in the options. Take the values of $\sqrt{10/M}$ for each gas as given there.)

During Searle's experiment, zero of the Vernier scale lies between $3.20\times10^{-2}$ m and $3.25\times10^{-2}$ m of the main scale. The 20th division of the Vernier scale exactly coincides with one of the main scale divisions. When an additional load of 2 kg is applied to the wire, the zero of the Vernier scale still lies between $3.20\times10^{-2}$ m and $3.25\times10^{-2}$ m of the main scale but now the 45th division of Vernier scale coincides with one of the main scale divisions. The length of the thin metallic wire is 2 m and its cross-sectional area is $8\times10^{-7}\ \mathrm m^2$. The least count of the Vernier scale is $1.0\times10^{-5}$ m. The maximum percentage error in the Young's modulus of the wire is

During an experiment with a metre bridge, the galvanometer shows a null point when the jockey is pressed at 40.0 cm using a standard resistance of 90 Ω, as shown in the figure. The least count of the scale used in the metre bridge is 1 mm. The unknown resistance is

A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it ?

An experiment is performed to obtain the value of acceleration due to gravity $g$ by using a simple pendulum of length $L$. In this experiment time for 100 oscillations is measured by using a watch of 1 second least count and the value is 90.0 seconds. The length $L$ is measured by using a meter scale of least count 1 mm and the value is 20.0 cm. The error in the determination of $g$ would be :

In the circuit diagrams (A, B, C and D) shown below, R is a high resistance and S is a resistance of the order of galvanometer resistance G. The correct circuit, corresponding to the half deflection method for finding the resistance and figure of merit of the galvanometer, is the circuit labelled as :

In an experiment for determining the gravitational acceleration g of a place with the help of a simple pendulum, the measured time period square is plotted against the string length of the pendulum in the figure.

What is the value of g at the place ?

The diameter of a cylinder is measured using a Vernier callipers with no zero error. It is found that the zero of the Vernier scale lies between 5.10 cm and 5.15 cm of the main scale. The Vernier scale has 50 divisions equivalent to 2.45 cm. The 24$^\text{th}$ division of the Vernier scale exactly coincides with one of the main scale divisions. The diameter of the cylinder is

In the determination of Young's modulus $\left(Y=\dfrac{4MLg}{\pi ld^2}\right)$ by using Searle's method, a wire of length $L=2$ m and diameter $d=0.5$ mm is used. For a load $M=2.5$ kg, an extension $l=0.25$ mm in the length of the wire is observed. Quantities $d$ and $l$ are measured using a screw gauge and a micrometer, respectively. They have the same pitch of 0.5 mm. The number of divisions on their circular scale is 100. The contributions to the maximum probable error of the $Y$ measurement

A student is performing the experiment of Resonance Column. The diameter of the column tube is 4 cm. The frequency of the tuning fork is 512 Hz. The air temperature is 38 °C in which the speed of sound is 336 m/s. The zero of the meter scale coincides with the top end of the Resonance Column tube. When the first resonance occurs, the reading of the water level in the column is

The density of a solid ball is to be determined in an experiment. The diameter of the ball is measured with a screw gauge, whose pitch is 0.5 mm and there are 50 divisions on the circular scale. The reading on the main scale is 2.5 mm and that on the circular scale is 20 divisions. If the measured mass of the ball has a relative error of 2%, the relative percentage error in the density is

To verify Ohm's law, a student is provided with a test resistor $R_T$, a high resistance $R_1$, a small resistance $R_2$, two identical galvanometers $G_1$ and $G_2$, and a variable voltage source V. The correct circuit to carry out the experiment is

A student uses a simple pendulum of exactly 1m length to determine g, the acceleration due to gravity. He uses a stop watch with the least count of 1 sec for this and records 40 seconds for 20 oscillations. For this observation, which of the following statement(s) is (are) true?